Following on my other post about
THE EXHIBIT THAT TRANSFORMED PHOTOGRAPHY comes this post from
history.com.
These Are the 10 Most Controversial Moments in the History of PhotographyI don't think they are in order of importance but more in a time line such as...
#1 - Death on Camera: Mathew Brady’s Civil War Photographs
In 1862, at the height of the Civil War, photographer Mathew Brady—whose 1864 portrait of Abraham Lincoln is visible on the $5 bill—organized an exhibition in his New York studio called “The Dead of Antietam.” For the first time, Americans saw images, primarily taken by Brady staffer Alexander Gardner, of the soldiers killed and maimed on the battlefield; the results were shocking. “Mr. Brady has done something to bring home to us the terrible reality and earnestness of war,” wrote The New York Times in October 20, 1862.
And a later image...
#5 - Robert Mapplethorpe Goes to Trial
In April 1990, Hamilton County prosecutors charged the Contemporary Arts Center of Cincinnati with obscenity for showing a collection of Robert Mapplethorpe’s work—included images of S/M and gay culture—entitled, “The Perfect Moment.” It was the first time in the nation’s history that a museum had been taken to criminal court for works it had chosen to display.
and...
#10 - Celebgate
Celebrities woke up to a new digital reality on August 31, 2014, when nearly 500 images—featuring celebrities, including Jennifer Lawrence, Amber Heard, Olivia Wilde and Anna Kendrick in various states of undress and posing in sexual situations—were posted online for the world to see.
I can see why those 10 images were selected...that's not to say there aren't other images like Capra's
Loyalist Militiaman at the Moment of Death
Time has a collection
The Most Influential Images of All Time like the portrait of Che Guevara.
Alberto Korda-The Photographer behind the Face of Ernesto Che Guevara
In the process of putting this list together, we noticed that one aspect of influence has largely remained constant throughout photography’s nearly two centuries. The photographer has to be there. The best photography is a form of bearing witness, a way of bringing a single vision to the larger world. That was as true for Alexander Gardner when he took his horse-pulled darkroom to the Battle of Antietam in 1862 as it was for David Guttenfelder when he was the first professional photographer to post directly to Instagram from inside North Korea in 2013. As James Nachtwey, who has dedicated his life to being there, put it some years ago, “You keep on going, keep on sending the pictures, because they can create an atmosphere where change is possible. I always hang on to that.”
The Time collection curated by Ben Goldberger, Paul Moakley and Kira Pollack
Another collection from
World History Charts.com offer another grouping (with some overlaps).
MOST FAMOUS PHOTOGRAPHSGreat photographs freeze a moment in time, often telling a story where words cannot. Famous pictures such as these create images which trigger our emotions and spark our imagination. 
Sallie Gardner at a Gallop Eadweard Muybridge 1878
Raising the Flag on Iwo Jima is a photograph taken on February 23, 1945, by Joe Rosenthal
Earthrise William Anders 1968
wow...I keep looking and find more collections...I gotta stop but you can keep looking...
Best Photographs in History
